Linq to Google shows an example of implementing IQueryable and IQueryProvider.

GLinq is an implimentation of the Linq deferred execution model for querying Google's data sources. The initial release can be used to query the Google Base. Subsequent releases will target support for YouTube, Calendar, Email, etc.

The ultimate goal of this project is to create a generic enough model to allow plugin providers for
any REST API.

I will be adding posts in the near future on how the code works. For now you have to play with it yourself.